


Cure Deanmon

by Northwind_ashland



Category: Supernatural
Genre: Castiel Has a Crush on Dean Winchester, Charlie Bradbury in the Men of Letters Bunker, Crossroads Demon Dean Winchester, Cure for the Mark of Cain (Supernatural), Dean Winchester Bears the Mark of Cain, Demon Cure used on Dean Winchester, Demon Dean Appreciation Day (Supernatural), Demon Dean Winchester, Demon Dean Winchester Being an Asshole, Demonic Possession, Human Castiel (Supernatural), Human Castiel in the Men of Letters Bunker (Supernatural), Hunter Castiel (Supernatural), Hunter Charlie Bradbury, Hurt Dean Winchester, M/M, Mark of Cain (Supernatural), No Cure for the Mark of Cain (Supernatural), Old Sam Winchester, POV Castiel (Supernatural), POV Charlie Bradbury, Post-Demon Dean Winchester, Post-Mark of Cain (Supernatural), Prince of Hell | Yellow-Eyed Demon Dean Winchester, Retired Hunter Sam Winchester, Teacher Sam Winchester
Language: English
Status: Completed
Published: 2021-03-10
Updated: 2021-03-10
Packaged: 2021-03-16 18:28:53
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,459
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29954112
Author URL: https://archiveofourown.org/users/Northwind_ashland/pseuds/Northwind_ashland
Summary: "You know about the men of letters?" Cas asked quickly. This was a mistake. The demon smiled, "yes I do, and you don't. That's interesting..." Cas's face hardened, "tell us about them." "Well, you see, in order for me to do that, you have to give me some information too." Charlie shook her head, "you're the one tied up. We can make you talk." "You guys are hunters. Don't you have morals? You wouldn't torture an innocent human." "You're a demon." "Oh, no, no. I promise. Get the holy water, I'll be fine. Go on." Hesitantly, Cas took his flask of holy water out of his pocket. He flicked some on to the man. The man closed his eyes but didn't burn at the holy water. "See?" the man smiled.or the one in which Sam could never cure Dean from being a demon and hunters/legacies Castiel and Charlie find him in the bunker
Relationships: Castiel & Dean Winchester, Castiel/Dean Winchester
Comments: 2
Kudos: 16





	Cure Deanmon

**Author's Note:**

> No trigger warnings needed

"What is this place?" Castiel wondered as he opened up the heavy pure iron door.

"Woah," Charlie lowered her gun as she stood beside Cas, "this is epic!"

They were standing on a balcony looking down at what looked like a massive library.

Charlie began exploring the machines to try and find out how they were getting power. Cas began skimming through the various books and files. After a couple of minutes, Charlie comes back into the main room.

"Dude," Charlie threw up her hands, "I have no idea how this place is getting power or running water. There's this motherboard but it looks ancient. Probably the most advanced computer they had 60 years ago."

Cas nodded, "these books are all lore and these files are cases that the Men of Letters worked. They cataloged everything."

"Wow, I wonder what else they have in this bunker."

"I don't know, we should probably explore it more."

Charlie smiled, "definitely."

They wandered through the various hallways. Finding other smaller libraries, storage rooms, or what appear to be living quarters that had long been abandoned.

The next room they enter looks like all the other storage rooms. Cas is about to move on when Charlie stops him.

"Cas look," she points to the ground, "scratch marks. I think-"

"It's a hidden door."

"Yeah. Let's open it!"

Charlie grabbed one of the shelf posts and Cas grabbed the other. They pulled out and the cabinets moved to reveal a hidden room.

Charlie gasped, "oh my god there's someone here!"

"No Charlie wait!" Cas put his arm out to stop her, "it's a demon. Look there's a devil's trap."

Cas inspected the man. His head was lulled over and he didn't appear to be breathing. He was handcuffed and tied to the chair. His white t-shirt and bluejeans were covered in dried blood.

"Wait is he- or it alive?"

"Well let's see."

Cas approached the man, who still was unconscious, and checked for a pulse.

Cas's eyes widened, "there's a pulse!"

"What happened?"

"I don't know, let's ask him." Cas shook the man's shoulders. No response. He slapped him. Still no response. He tried slapping him again. This time the man gasped and opened his eyes.

Cas stepped back and told Charlie to do the same.

The demon began coughing, "ugh, what was that for?"

"You were unconscious, demon," Cas spat.

"What- no- I'm not a demon- who are you?"

"We ask the questions," Charlie crossed her arms.

The demon looked up to her and tilted his head, "you guys aren't men of letters."

"You know about the men of letters?" Cas asked quickly. This was a mistake.

The demon smiled, "yes I do, and you don't. That's interesting..."

Cas's face hardened, "tell us about them."

"Well, you see, in order for me to do that, you have to give me some information too."

Charlie shook her head, "you're the one tied up. We can make you talk."

"You guys are hunters. Don't you have morals? You wouldn't torture an innocent human."

"You're a demon."

"Oh, no, no. I promise. Get the holy water, I'll be fine. Go on."

Hesitantly, Cas took his flask of holy water out of his pocket. He flicked some on to the man. The man closed his eyes but didn't burn at the holy water.

"See?" the man smiled.

"How are you alive then?" Charlie asked.

"That's a long story. Why don't you tell me what year it is?"

"It's 2038, what year did you think it was?" Cas squinted his eyes.

"2038?" He sighed, "I've been unconscious for almost 30 years."

"I thought the men of letters died out 60 years ago."

"Well that's complicated and A long story, but will you untie me? I've proved I'm human."

Charlie bent down but Cas pulled her back.

He narrowed his eyes, "if you're human, why are you tied up?"

Dean rolled his eyes, "another long story. Now untie me, please?"

"Tell us first."

The man made a huge smile. "So you're not going to untie me?"

"No, just talk."

The demon's face completely relaxed, "whatever." His whole demeanor changed. He squeezed his eyes shut in concentration. The room started rumbling.

"What are you doing?"

"Cas!" Charlie screamed, "what's happening? I thought he was human?"

"I don't- I don't know!"

The demon's cuffs started glowing. The table in the corner of the room was clattering. Things started falling off. Papers, syringes, and ... a blood bag?

The cuffs dissolved into molten metal and the shaking stopped. The man smiled and pulled his arms out of the ropes, one arm at a time.

"I guess I still got it."

Cas pulled out an angel blade and Charlie pulled out the demon knife.

"Stop!" Charlie demanded.

The demon laughed, "you have no idea what you walked into, huh?"

"We've killed demons before."

"Oh I'm sure you have," he started slowly walking towards them, "but I'm not just any other demon. Those won't work on me."

The two hunters slowly stepped back. "This is an angel blade and that is the demon-killing knife."

The demon had a wicked grin on his face, "well if you're so confident, why don't we fight?"

Cas wasted no time. He lunged at the demon who blocked his arm. He pushed Cas back just as Charlie dove in. She had her knife almost against the demon's throat. He was pushing back against her though. They were at that standstill for a moment. Then Cas stabbed the demon in the back with the angel blade. The demon yelled and let go of Charlie. She and Cas stepped back and watched in confusion. The demon didn't glow and die like the others. He grunted and reached around to his back. He grabbed the blade and pulled it out. He stretched his shoulders as his body healed.

"No," Cas muttered.

"Yeah," the demon smiled, "I told y-"

Charlie threw the demon-killing knife right into his heart. He stumbled back a couple of steps, then glared at Charlie.

"I told you," he grunted as he pulled the knife, "there's only one thing that can kill me."

The hunters stared at the demon, breathing hard.

The demon put his hand half up, "what you aren't gonna run? Not gonna get out of the way?"

"You're still in the devil's trap," Charlie said.

"Oh?" the demon looked down. He put his hand on his heart and looked at Charlie with mocked thankfulness, "thanks for reminding me."

He takes a few steps forward, then one over the devil's trap. He smiled, "you can thank my brother for that."

"Go, run!" Cas called. He headed for the door, Charlie right behind him. The demon followed slowly behind them. When he left the room, alarms started going off.

The hunters ran to the front door but found it was locked up tight.

"Whoever that demon is, the men of letters didn't want it to escape," Cas said.

"Whoever I am?"

Cas and Charlie whipped around. The demon was standing behind them.

"You really haven't heard of me?" the demon laughed, "I'm Dean freakin Winchester."

The hunters glanced at each other.

"No?" Dean put his hands on his hips, "well that makes me sad. I suppose you don't know where the First Blade is then."

"The First Blade?" Charlie asked.

"Yeah, it's the only thing that can kill me," Dean turned around, "and it's somewhere in this bunker."

He started walking away.

"Why would you tell us that?" Cas started following Dean who just laughed and kept walking.

"You're not going to kill us?" Charlie asked.

"Why would I do that?" Dean stopped and turned around, "you can help me find it."

"We'd never help you." Cas spat.

"Oh not on purpose, no. You see the only way for you to get out of here is to stop the lockdown. The only way to stop the lockdown is to A. get me back in that dungeon, which is never going to happen, or B. kill me. So if you don't want to starve to death I suggest you get going."

Dean left and began searching through each room. He could feel the blade's presence somewhere close, but nothing exact. Hours pass and he narrows it down to one room. He searches and searches but it's not there.

"Son of a bitch!" he picks up a chair and throws it across the room. The wood splinters fly around the room near the door. He sees one of the humans peer into the room.

"What!" Dean growls.

"Having difficulties?" the man asked.

"I know it's here, but I can't find it."

The woman came and stood beside the man in the doorway, "Is this place really locked down until you die?"

"Yeah, well I can blast through the door, but I'm not leaving without my blade. So if you find it... we can make a deal."

Cas narrows his eyes, "You expect us to just give you the blade and you'll just let us live."

"Oh I'd be _so_ grateful, besides, do you have any other option."

Charlie crossed her arms, "there's an override switch."

"No, I don't think so. Why would you come here then? No, you're desperate because I bet that my brother disabled the override switch when he left. He couldn't risk me using it to escape. You're not even men of letters. You have no idea how this place works. You're trapped and helpless and now you've come crawling to a demon for help."

"What do you want?" Cas growled.

"The blade is in this room somewhere. I can feel it, but it is warded and I can't find it. If you find it, then give me the blade, I'll get you out of here alive."

"Then you'll just kill us outside."

"Very impressive sir, I guess I'm really not your first demon. Ok, fine, you have my word, that, as long as you don't try and kill me, I promise to get you out of here and not to kill or hurt you at all for 10 years, good?"

"You won't take our souls?"

"No. Even trade. Job for a job."

Cas glanced at Chalie. She shrugged, "seems legit."

Cas looked back at Dean, "you have a deal."

"Come here pretty boy," Dean beckoned with a finger.

Cas rolled his eyes and walked over. Dean grabbed Cas's face, surprisingly gently, and began passionately kissing. Cas kept his hands down but slightly kissed Dean back. When Dean finally pulled away, he kept his hands on Cas's face.

He licked his lips and said, "what's your name?"

"Castiel."

"Well get to work, Cas."

Charlie was standing in the doorway, "uh do I have to kiss you too."

Dean finally took his hands and eyes off Cas and looked at Charlie, "no his can count for both of you uh..."

"Charlie. What exactly are we looking for?"

"The First Blade is the jaw of a snake, kinda. You'll know when you see it. Alright, you stay here, and I'll go turn that _annoying_ alarm off." Dean started to leave.

"Wait what?" Cas stood and turned around, "you can just turn off the shutdown?"

"No, but I can stop the blaring sound and the flashing lights. The door will stay closed. Get to work."

Cas rolled his eyes but began searching the room with Charlie. Dean was gone for a while, but the alarm stayed on. They look through drawers and boxes, finding nothing. Until a curious Charlie started checking out the books.

"Cas," Charlie whispered, "get over here."

Cas hurried over to her, "what?"

"I found it, I think." She holds up a big book. When she opens it, the inside of the pages are cut out to make space for a box. It's a highly warded box. Cas takes it and opens it. He picks up what's inside. It's almost like a curved bone with what looks like teeth along parts of the edge.

"Is this it?" he asks in a whisper.

"I think so."

"We can't give it to him. He'd be too dangerous."

"Then we kill him with it. I'll distract him when he comes back and you jump him from behind."

"That seems like our best option. Why could this bone thing kill him but not an angel blade?"

"I guess-" Charlie stopped because the alarms stopped. The lights returned to normal.

"He's coming back. Go over there behind the door."

Cas does what Charlie says and they wait. Charlie closes the warded box and faces away from the door.

Dean comes back, but he doesn't enter the room. He leans against the door frame, "where's the guy?"

"Oh, he went to find you," Charlie turned around, "I think we found it."

Dean stood up and walked over to her. Cas quietly comes up behind Dean and stabs him in the back.

"Son of a- mmm god." Dean hissed. He stumbled back and glared at Cas.

"You- you didn't die," Charlie gasped.

"You lied!" Cas yelled.

Dean let out a pained laugh, "no, no. I didn't lie. Not really. You see, this blade is the only thing that can kill me, but the First Blade can only be wielded by someone with the Mark of Cain."

Dean extended out his right hand and pointed at what looked like a burn mark. Charlie and Cas backed off. He was blocking the exit. They were trapped. Dean stuck his arm out and Cas felt the blade tug at his arm.

"What? How?"

Dean smiled, "it's my blade. Yes, it's the only thing that can kill me, but I'm the only one who can use it."

Cas's arm was pulled forward as the blade was summoned. He had no choice but to let go. The blade flew through the air and right into Dean's outstretched hand. Dean grasped the blade and held it out. He had a wicked grin and bloodlust in his eyes as the Mark started to glow.

"You made a deal to let us live!"

"You were the one that ended the deal when you attacked-" Dean started coughing, "what the- cough- what are you doing?"

The hunters stared in shock as a shining purple glowing chain appeared around Dean.

"No! No!" his scream becomes demonic.

"Go, go!" Charlie yells. They run out of the room but Dean's screams don't stop. The bunker door is still locked tight. So they stop and catch their breath in a random storage room.

"What the hell is going on here?" Charlie asks once things are calm.

Cas sighed, "I don't know, but I think the demon is trapped in that room."

"For now."

"Ok, why don't you go to the electrical room and see if you can get the door open. I'll search the dungeon, see if I can find any clues on the First Blade or the demon Dean."

Charlie nodded, "good luck."

"Yeah, you too."

\------

Cas entered the dungeon with trepidation. He knew the demon wasn't there, but he wasn't sure what to expect. There were tons of files on the table. Hopefully, some of them would explain the unkillable demon, the Mark of Cain, and the First Blade.

The files talk about a demon named Crowley who apparently was the king of hell. He was the one who brought Dean, human Dean, to meet Cain. That's when Dean got the mark, but not when he turned into a demon. _Apparently, there are knights of hell?_ The First Blade is the only thing that can kill them. So Dean got the mark and the blade in order to kill Abadon. But the Mark isn't just a mark, it made Dean act aggressively. Then Dean died. At the hands of an Angel. _So I guess Angels are real too_. That's when Dean became a demon. His brother Sam tracked him down and brought him back to the bunker. He wanted to cure him. _Cure a demon?_ The file details the process and requirements for the cure. Dean's treatment was finished but apparently, it didn't work. Not completely.

He went to Charlie and told her everything.

"Sam cured him for being a demon, but his state of mind didn't return because of the Mark of Cain. They found a way to take the Mark off, but they never did it."

"Why?" Charlie asked.

"Well, they need a hand of God."

"A hand of God? Didn't the prophet say-"

"I know-"

"You're necklace is a hand of God! We can use it to cure Dean and then-"

"-then we hope the bunker lets us out."

"Well Dean lived here so if it comes to that, hopefully, he can help us once he's cured."

They gather the few other ingredients needed for the spell and head to the storage room.

Dean is standing in the same place they left him, clinging tight to the blade.

"Well well, you can't get out so you've come to make another deal huh?"

"No, we're here to cure you."

Dean laughed, "oh god, you found Sammy's research. He tried that already and it just made me immune to holy water and devil's traps."

"Well, we have a hand of God."

Dean raised his eyebrows, "a hand of God? You just happen to have a hand of God with you?"

Cas took his necklace off and put it into the spell bowl.

"How did you get that."

"None of your business."

Dean rolled his eyes, "it's not gonna work. My brother tried that already."

"Maybe he didn't have a real hand of God," Charlie suggests as she stirs the ingredients of the spell.

Charlie began chanting the spell. They could see the effect it was having on Dean. It started with minor face twitches and painful grunts but it soon turned into agonizing screams. When the spell was done, there was a blinding black light. Dean stumbled back and slumped against the wall. The purple chains disappeared. Cas took his angel blade out. Dean stayed on the ground holding his head.

"Did it work?" Charlie asked.

Cas hesitantly stepped forward, "Dean, is that you?"

Dean was muttering to himself, "oh my god oh my god oh my god oh my god oh my god."

"Dean?"

Dean's gaze shoots up at the hunters. His voice was shaking, "was that real? Did that really happen?"

"Yes. Is the Mark gone?"

Dean showed his arm to them, "yes," he laughed as tears formed in his eyes, "yes it's gone."

Cas put his blade away and kneeled down next to Dean, "good to have you back."

Dean reached his arms around and hugged Cas, "thank you thank you thankyou thankyouthankyou."

Cas awkwardly hugged Dean back, "of- of course."

"Wait, wait!" Dean pulled away and his tears stopped falling, "is it really 2038?"

"Yes," Charlie answered.

"I-I haven't- I haven't seen my brother since he was 25 and now- now he's 55? That's oh god, that's if he's even alive. God, I'm still 30. What will- oh god- he'll try and kill me- I'll freak him out- he'll think he escaped- I-I-I can't I-"

"Dean breathe," Cas put his hand on his shoulder, "just breathe."

Charlie sat down on the other side of Dean, "we're going to help you, Dean. It's ok."

Dean took a few deep breaths with their help. Then spoke again, "the things I said, the things I did to my brother..."

"That wasn't you Dean," Charlie smiled at him, "your brother knows that."

He struggled to stand up, "I need to find him. I need to apologize."

Cas stood and offered a hand to Dean. He took it as Cas spoke, "we need to make sure the bunker door is unlocked."

Dean whipped the tears off his face, "I'm sure it is, but yeah, let's check."

They follow Dean to the main door.

"If it is locked, we can always try the garage."

Cas reached out to the door and pulled. It opened.

Charlie sighed with relief, "Wow, how'd that even work?"

"It was a spell. As long as there was a demon, as long as I was in here, the door would stay locked. The spell activated the lockdown when I left the dungeon. My brother was always smart, he had another spell that bound me when I came in contact with the First Blade."

"Where is the First Blade?" Cas asked.

"I left it in that room," Dean scratched the back of his neck, "I don't want to look at it anymore."

"Ok Dean," Cas smiled, "let's go find your brother."

They leave the bunker and get into Cas and Charlie's car. Charlie pulls out her computer.

"Sam Winchester is your brother's name right?"

"Yeah," Dean scooched up and peered over Charlie's shoulder.

"Is this him?" She pulled up a photo.

Dean's eyes watered and he smiled, "Yeah. Yeah. That's him. I've- I've never seen him with a beard before ha, he's so old and- and he's all grown up."

"It says he's a history professor here in Kansas."

"U Kansas?" Cas asked.

Charlie nodded.

"Alright let's go." Cas started the car and pulled onto the road.

"Um, do you guys mind if we stop somewhere?" Dean requested, "I uh I haven't eaten in like 30 years."

Cas chuckled softly, "of course. Craving anything in particular?"

"Burgers. Let's get burgers."

So they do. Dean eats like he's starving, which he literally is. He gets seconds and finishes both of his burgers before Cas or Charlie finish theirs.

"So how'd you two find the bunker?" Dean asked.

"We were visited by a prophet," Charlie answer.

"She was the one who gave me the hand of God necklace," Cas added.

"Apparently I'm a legacy. So she gave me the key."

"Huh, I'm a legacy too. Did the prophet say anything?"

"No, she was," Cas shook his head, "very mysterious."

"Alright, well it's another 3 hours to the University of Kansas so do you think we can get going?"

"Of course, Dean," Charlie smiles and throws some cash down on the table.

When they get to the car, Charlie drives instead of Cas. Dean announces he's going to get some shut-eye in the back seat and they set off. Cas looks up Sam of the university website. It says he has open office hours from 7-9 pm. Which is perfect because they should get there around 8:45.

Cas wonders what the meeting will be like. He looks back at Dean, who is passed out in the back seat. _He's cute when he sleeps._

"Ok, Cas," Charlie laughs.

Cas's eye widened "Did I say that out loud?"

"Yup."

Cas feels heat rush to his cheeks "I just meant he looks so peaceful now. It's nice. He's obviously been through so much."

"Whatever you say Cas."

He changes the subject, "how do you think his brother will take this?"

"I don't know, but they're brother's he's got to at least listen."

Dean wakes up when they're about 15 minutes out. He's fidgeting around in his seat, obviously nervous about seeing his brother.

"Ok guys. I think," Dean sighs, "I think you two should go in first, just to explain. Then I'll come in after."

"Are you sure?" Charlie asked.

"Yes. If he sees me he'll- he'll probably go straight to attacking."

Cas nodded, "That makes sense."

Charlie parks the car in front of the history building. They follow the signs inside the building to Sam's office.

"I'll wait here," Dean says a couple of yards away from the door, "you guys go knock."

Charlie put her hand on Dean's arm and gave him a reassuring smile. Then she joins Cas and he knocks on the door.

"Come in," a voice says from inside.

They enter and see Sam sitting at his desk working on his computer.

"Hello, um, I'm sorry what class of mine are you in?" Sam smiled and motioned for them to sit, "I don't recognize either of you."

They sit and Charlie talks, "Actually sir, uh, we're hunters."

The smile drops from Sam's face, "oh. Well, I'm retired. I guess I could help you with some lore but I don't go on hunts anymore."

"Actually," Cas bit his lip, "we're not here for your help."

Sam furrows his eyebrows, "what are you here for then?"

"We cured Dean," Charlie blurted.

Sam clenched his fist, "no not possible. Who sent you? Huh!"

"Sam it's the truth," Cas tried

"It's not possible," Sam stood up, "I tried _everything_ to cure my brother. So who are you?"

Cas put up his arms in defense, "We're legacies. We found the bunker-"

"You went into the bunker?"

"Yes"

Sam got a flask of holy water and quickly flicked some at the hunters.

Charlie stood up, "We're human and so is your brother. We removed the mark."

"How?" Sam yelled.

Cas kept his voice even, "We had a hand of God and we used the spell."

"That spell is fake. Hands of God don't exist!"

"They do Sammy," Dean said from the doorway. He had tears in his eyes.

Sam just stared at him breathing heavily.

"Look," he showed Sam his arm, "the mark's gone."

Sam covered his mouth, "Dean." He rushed over. Dean was hesitant at first, worried his brother might attack him. But he didn't Sam opened his arms wide and brought Dean into a hug.

"Dean, I'm sorry I failed you I failed I abandoned you," Sam cried into Dean's shoulder.

"No Sammy, it's ok," he rubbed circles in Sam's back, "you did your best."

Sam pulled away, "Dean, I left you down there because I thought you couldn't be saved and I couldn't kill you. The only way I was able to leave is knowing that I did everything. That there was no solution, but I was wrong. I was told that hands of God don't exist. Dean, I'm so sorry for giving up on you, please forgive me."

"Sammy, you don't have to apologize," Dean smiled at his brother, "I'm the one that needs to apologize. The things I said, the things I did."

"Dean, that wasn't you. I don't care about any of that. I should have never stopped trying. I should-"

"I forgive you, Sammy."

Sam smiled while his eyes watered, "I forgive you too, Dean."

They hug again and let the tears flow. Remembering they weren't alone, they pulled apart.

Dean whipped his face, "uh this is Castiel and Charlie. They're legacies. They saved me."

"I can't thank you two enough," Sam shakes both their hands, "I will never be out of your debt."

"Dude, it's all good," Charlie smiled, "honestly."

"I've got to tell you man," Dean shook his head, "that beard makes you. God, I can't look at it."

"Jerk."

"Bitch."

**Author's Note:**

> Please leave a comment if you enjoyed! The end was kinda rushed but whatever :)


End file.
